Column-row addressable electric microswitch arrays and sensor matrices employing them

a technology of a sensor matrix and an array of adsorption electrodes, which is applied in the direction of optical radiation measurement, radiation control devices, instruments, etc., can solve the problems of inability to meet the requirements of large-scale sensor applications, the performance of the early device is not good, and the switch made with discrete mechanical relays is too bulky

Inactive Publication Date: 2002-09-19
LG CHEM LTD +1
View PDF0 Cites 26 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Switches made with discrete mechanical relays are too bulky, too large in size and often too slow in switching speed for this application.
However, the material and the process costs have limited the use of such active matrix arrays in large size sensor applications.
However, the performance of these early devices (as determined by their I-V characteristics) was insufficient to enable use as electric switches.

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Column-row addressable electric microswitch arrays and sensor matrices employing them
  • Column-row addressable electric microswitch arrays and sensor matrices employing them
  • Column-row addressable electric microswitch arrays and sensor matrices employing them

Examples

Experimental program
Comparison scheme
Effect test

example 1

[0100] MSM devices were fabricated in the structure shown in FIG. 1. The anode electrode (11) used in this Example was an indium doped tin oxide (ITO) layer with work function close to 4.8 eV and surface resisitivity of .about.20 .OMEGA. / square. A 7 mil Mylar film was used as the substrate (14) for this device. A thin layer of MEHPPV (.about.1500.ANG.) was spin cast onto the ITO electrode at room temperature. Details on the synthesis and process of MEH-PPV can be found in literature [F. Wudl, P. M. Allemand, G. Srdanov, Z. Ni, and D. McBranch, in Materials for Nonlinear Optics:Chemical Perspectives, Ed. S. R. Marder, J. E. Sohn and G. D. Stucky (American Chemical Society, Washington, DC, 1991) p. 683]. A thin layer of Ca (500-5000.ANG.) was then thermally evaporated as the cathode electrode (the Ca was typically over-covered by a protective layer Al). The active area of each device was 0.1 cm.sup.2.

[0101] FIG. 5A shows the device current as a function of bias voltage. Forward bias i...

example 2

[0108] The experiments of Example 1 were repeated with Au as the anode and Al as the cathode. The device size was reduced to .about.0.0004 cm.sup.2, comparable to that of a pixel in a microswitch matrix for image sensor applications. The I-V characteristics and the rectification ratio are shown in FIG. 6A and 6B. The rectification ratio and the ON / Off ratio at 5V and 0V were .about.5.times.10.sup.5 and >10.sup.7, respectively.

[0109] Similar devices were fabricated with different metal cathode, including Sm, Y, Pr, MgAg, MgAl, Li, Ba, Ag, Cu, In, Hf etc. Similar switching effect was observed in each case.

[0110] Similar devices were fabricated with a thin buffer inserting between the semiconducting layer and the cathode layer. Examples of the buffer layer include inorganic compounds such as LiF, BaO, BaF.sub.2, Li.sub.2O. Organic molecules can also be used for the buffer. Examples include OCA and its derivatives. Similar switching effect was observed in each case.

[0111] Organic molecu...

example 3

[0118] The experiments of Example 1 were repeated with ITO as the anode and Al as the cathode. An MEH-PPV:PCBM blend film (1:1 weight ratio) was used as the semiconducting layer 12, which was spin cast from solution in xylenes (concentration of approximately 0.5 wt %). PCBM is a fullerene molecule with molecular structure and chemical properties similar to C.sub.60 (a form of C molecule in buckyball shape). Details about its synthesis and characterization has been documented in literature [J. C. Hummelen, B. W. Knight, F. Lepec, and F. Wudl, J. Org. Chem. 60, 532 (1995)]. The I-V characteristics and the rectification ratio are plotted in FIG. 7A and 7B. The rectification ratio was larger than 4.times.10.sup.5 for bias over 1.5 V and the ON / Off ratio operating at 2V and 0V was >3.times.10.sup.7.

[0119] Similar results were obtained from ITO / MEH-PPV / C.sub.60 / Al, ITO / TPB / Alq3 / Al devices in which the semiconducting layer was in a bi-layer structure reminiscent of the so-called heterojunc...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

PUM

PropertyMeasurementUnit
current densitiesaaaaaaaaaa
temperatureaaaaaaaaaa
temperatureaaaaaaaaaa
Login to view more

Abstract

The present invention relates generally to fabricating two-terminal electric microswitches comprising thin semiconductor films and using these microswitches to construct column-row (x-y) addressable microswitch matrices. These microswitches are two terminal devices through which electric current and electric potential (or their derivatives or integrals) can be switched on and off by the magnitude or the polarity of the external bias. The microswitches are made from semiconducting thin films in a electrode / semiconductor / electrode, thin film configuration. Column-row addressable electric microswitch matrices can be made in large areas, with high pixel density. Such matrices can be integrated with a sensor layer with electronic properties which vary in response to external physical conditions (such as photon radiation, temperature, pressure, magnetic field and so on), thereby forming a variety of detector matrices.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001] This application claims the benefit of U.S. Provisional Application No. 60 / 073,411, filed Feb. 2, 1998, which application is incorporated herein by reference in its entirety.BACKGROUND OF THE INVENTION[0002] 1. Field of the Invention[0003] The present invention relates generally to the fabrication of electric microswitches with thin semiconductor films and column-row (x-y) addressable electric switch matrices constructed with such microswitches. These microswitches are two terminal devices through which electric current, electric potential or their derivatives or integrals can be switched on and off by the magnitude or the polarity of an external bias. They are made of semiconducting thin films in metal / semiconductor / metal, thin film configuration. Column-row addressable electric micro-switch matrices can be made to cover large areas, with high pixel density. Such matrices can be integrated with one (or several) additional layer(s) with ...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Application Information

Patent Timeline
no application Login to view more
Patent Type & Authority Applications(United States)
IPC IPC(8): H01L21/00G01J1/02H01L27/144H01L27/146H01L27/24H01L27/28H01L27/30H01L29/47H01L29/872H01L31/09H01L35/24H01L45/00H01L47/00H01L49/02H01L51/00H01L51/05H01L51/30H01L51/42
CPCB82Y10/00H01L27/1446H01L27/14609H01L27/14643H01L27/14667H01L27/14676H01L27/14687H01L27/28H01L27/285H01L27/30H01L27/307H01L27/308H01L51/0034H01L51/0035H01L51/0036H01L51/0037H01L51/0038H01L51/0041H01L51/0046H01L51/0047H01L51/0081H01L51/0583H01L51/0591H01L51/4206H01L51/424H01L51/4253Y02E10/549H10K19/202H10K19/00H10K39/00H10K39/36H10K39/32H10K85/10H10K85/113H10K85/143H10K85/111H10K85/1135H10K85/114H10K85/211H10K85/215H10K85/324H10K10/26H10K10/50H10K30/451H10K30/30H10K30/20H10K30/00
Inventor YU, GANGCAO, YONG
Owner LG CHEM LTD
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap